docs: def _blank_param_value(value):
          """Remove the content from *value* while keeping its whitespace.
  
          Replace *value*\\ 's nodes with two text nodes, the first containing
          whitespace from before its content and the second containing whitespace
          from after its content.
          """
          sval = str(value)
          if sval.isspace():
              before, after = "", sval
          else:
              match = re.search(r"^(\s*).*?(\s*)$", sval, FLAGS)
              before, after = match.group(1), match.group(2)
          value.nodes = [Text(before), Text(after)]